JP2006232100A - Driving force distribution and controlling device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving force distribution and controlling device for vehicle capable of reducing irregular feeling applied to a driver when the driver turns right or left and further reducing a load applied to some driving system components. <P>SOLUTION: There is provided a vehicle having a driving power distribution and controlling means for controlling a distribution of driving power of at least one of the front and rear wheels and the right and left wheels. The driving power distribution and controlling means is formed as means for executing a pre-assumed driving power distribution and controlling operation before starting its rightward or leftward turning in response to a planned turning point information where its own vehicle plans to enter next on a running course. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention belongs to the technical field of a vehicle driving force distribution control device including a driving force distribution control means for controlling the driving force distribution of at least one of front and rear wheels and left and right wheels.

Conventionally, in a vehicle equipped with a driving force distribution control means for controlling the driving force distribution between the front and rear wheels and the left and right wheels, the purpose is to return to the intended turning line in response to the driver's steering operation when the vehicle understeer occurs. The stronger the degree of understeer detected by the difference between the turning radius and the target turning radius, the more the driving force distribution is controlled on the side of obtaining the vehicle moment in the oversteer direction (for example, in the case of an FF-based four-wheel drive vehicle, the transfer clutch (A control for increasing the driving force distribution ratio to the rear wheels, which are auxiliary driving wheels) (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 5-185859

  However, in the conventional vehicle driving force distribution control device, when the vehicle speed is high and the turning radius is small, large driving force distribution is performed in a short time (rapidly) to the sub driving wheels. There is a problem that the driver feels uncomfortable and the burden on the drive system components increases.

  The present invention has been made paying attention to the above problems, and an object of the present invention is to provide a vehicle driving force distribution control device capable of reducing a sense of incongruity given to a driver and a load on driving system components when the vehicle turns. And

In order to achieve the above object, in the present invention, in a vehicle provided with driving force distribution control means for controlling the driving force distribution of at least one of the front and rear wheels and the left and right wheels,
The driving force distribution control means is configured to execute a driving force distribution control that is assumed in advance from the start of a turn based on turning point information that the vehicle is scheduled to enter next on a traveling course.

  Therefore, in the driving force distribution control device for a vehicle according to the present invention, the driving force distribution control means predicts the driving force distribution that is assumed in advance based on the turning point information that the vehicle is scheduled to enter next on the traveling course. Control is executed before the start of turning. That is, when the vehicle is turning, the driving force distribution control that is assumed in advance is executed before the start of turning, so that the change of the driving force distribution ratio can be advanced before entering the turning point. The target driving force distribution ratio is almost achieved at the time of entering, and it is not necessary to apply the driving force rapidly after entering the turning point. As a result, it is possible to reduce the uncomfortable feeling given to the driver and reduce the load on the drive system components when the vehicle turns.

  Hereinafter, the best mode for carrying out a driving force distribution control device for a vehicle according to the present invention will be described based on a first embodiment shown in the drawings.

First, the configuration will be described.
FIG. 1 is an overall system diagram showing a hybrid four-wheel drive vehicle to which the driving force distribution control device of Embodiment 1 is applied.
As shown in FIG. 1, the hybrid four-wheel drive vehicle of Embodiment 1 includes an engine 1 (first drive source), a front motor 2a (first drive source), a rear motor 2b (second drive source), a left Front wheel tire 3a (main drive wheel), right front wheel tire 3b (main drive wheel), left rear wheel tire 3c (sub drive wheel), right rear wheel tire 3d (sub drive wheel), front differential 4a, A rear differential 4b and a transmission 5 are provided.

  The front motor 2a and the rear motor 2b perform both power running and regeneration as motor generators.

  The left and right front wheel tires 3a, 3b are driven by at least one of the engine 1 and the front motor 2a as a drive source, and the driving force that has passed through the transmission 5 is equally distributed by the front differential 4a.

  The left and right rear wheel tires 3b and 3c are driven by the driving force that has passed through the rear differential 4b that can control the driving force distribution to the left and right wheels, using only the rear motor 2b as a driving source. The driving force distribution control to the left and right wheels by the rear differential 4b includes the engagement force control of the differential limiting clutch set in the rear differential 4b and the engagement force for the left clutch and the right clutch set in the rear differential 4b. Controlled.

  As shown in FIG. 1, the driving force distribution control system of the hybrid four-wheel drive vehicle of Embodiment 1 includes a wheel speed sensor 6, a GPS 7 (Global Positioning System), a map information system 8, and a steering. An angle sensor 9, a blinker switch 10, a controller 11, a high-power battery 12, a front inverter 13a, and a rear inverter 13b are provided.

  The wheel speed sensor 6 includes a left front wheel speed sensor 6a, a right front wheel speed sensor 6b, a left rear wheel speed sensor 6c, and a right rear wheel speed sensor 6d, and obtains vehicle speed information of the host vehicle.

  The GPS 7 and the map information system 8 constitute a navigation system that guides the vehicle to the destination by taking the shortest arrival time route in consideration of traffic information and the like. In other words, when the driver inputs the destination, a map of the current driving area is displayed (map information system 8), and the traveling course set according to the vehicle position (measured by GPS 7) and the destination is displayed on the map. To do. The map information system 8 obtains turning radius information of the turning point at which the host vehicle is scheduled to enter next. The distance from the vehicle position to the turning point is also obtained by the GPS 7 and the map information system 8.

  Information on the steering angle during turning is obtained from the steering angle sensor 9. Further, the winker operation information of the driver is obtained from the winker switch 10.

  The controller 11 reads information from the wheel speed sensor 6, the GPS 7, the map information system 8, the steering angle sensor 9, and the winker switch 10, and before entering the turning point where the vehicle is scheduled to enter next on the traveling course. The driving force distribution ratio of the front and rear wheels is commanded to control the driving force of the engine 1, the front motor 2a, and the rear motor 2b. Further, when entering the turning corner, the left / right driving force distribution ratio is determined, and the rear differential 4b is controlled.

  The high-power battery 12 supplies power to both motors 2a and 2b via both inverters 13a and 13b, and also serves to collect power generated by both motors 2a and 2b.

  The front inverter 13a and the rear inverter 13b serve to supply the electric energy of the high-power battery 12 to both the motors 2a and 2b and to return the electric energy regenerated by the motors 2a and 2b to the high-power battery 12.

  Next, the operation will be described.

[Driving force distribution control processing]
FIG. 2 is a flowchart showing the flow of the driving force distribution control process executed by the controller 11 of the first embodiment. Each step will be described below (driving force distribution control means).

  In step S1, it is determined whether or not the traveling course is grasped in advance by setting the traveling course using the navigation system. If there is no course setting, the process proceeds to step S2. If there is a course setting, step S12 is performed. (Traveling course determination means).

  In step S2, following the determination that there is no course setting in step S1, the vehicle position on the traveling course is confirmed based on information from the GPS 7, and the process proceeds to step S3.

  In step S3, following the vehicle position confirmation in step S2, the traveling course information determined by the vehicle position and the destination is confirmed by the GPS 7 and the map information system 8, and the process proceeds to step S4.

  In step S4, following the traveling course information confirmation in step S3, the turning radius information of the turning point to be entered next is acquired from the own vehicle position information, the map information, and the own vehicle speed information, and the process proceeds to step S5.

  In step S5, following the turning radius information acquisition of the turning point to be entered next in step S4, the distance information from the own vehicle to the turning point is acquired from the own vehicle position information and map information, and the process proceeds to step S6. To do.

In step S6, following the acquisition of the distance information to the turning point in step S5, the driving force distribution control start point is determined, and the process proceeds to step S7 (control start point determining means).
Here, “determination of the driving force distribution control start point” is determined according to the turning radius R and the vehicle speed V. For example, as shown in FIG. The start point of the driving force distribution control is set to a point far from the turning point (large flying point) as the turning radius R of the turning point scheduled to enter next is smaller.

  In step S7, following the determination of the driving force distribution control start point in step S6, it is determined whether or not the vehicle position has reached the driving force distribution control start point. If NO, the process returns to step S2, and YES is determined. In this case, the process proceeds to step S8. In addition, after the second round of the flow for the same corner, only a check that the driving force distribution control start point has been reached is performed.

In step S8, following the determination of the driving force distribution control start point entry in step S7, the rear wheel driving force distribution ratio is determined, the front and rear wheel driving force distribution control is started, and the process proceeds to step S9.
Here, “determination of rear wheel driving force distribution ratio” means that, as shown in FIG. 4, the horizontal axis represents a value obtained by dividing the vehicle speed V by the turning radius R, and the rear wheel driving force distribution increases as the value of V / R increases. It is determined by the characteristic that increases the ratio Tr. In other words, the rear wheel driving force distribution ratio Tr is increased as the vehicle speed is higher at the same turning radius, and the rear wheel driving force distribution ratio Tr is increased as the turning radius is decreased at the same vehicle speed V. Then, when the rear wheel driving force distribution ratio is determined, each of the target front wheel driving force and the target rear wheel driving force is calculated based on the total driving force determined by the required driving force at that time and the rear wheel driving force distribution ratio. Until the turning point is reached, gradually obtain a target front wheel driving force and a target rear wheel driving force, or a value close to the target front wheel driving force and a value close to the target rear wheel driving force. Control for changing the driving force is started (first target front and rear wheel driving force distribution ratio setting means).

  In step S9, following the start of front and rear wheel driving force distribution control in step S8, it is determined whether or not the vehicle has entered a turning point based on the vehicle position information and map information. If NO, the process returns to step S8 to return to the front and rear wheels. The driving force distribution control is continued. If YES, the process proceeds to step S10.

In step S10, following the entry determination to the turning point in step S9, the left / right driving force distribution ratio of the rear wheels is determined, right / left wheel driving force distribution control is started, and the process proceeds to step S11.
Here, as shown in FIG. 5 (a), “determining the left / right wheel driving force distribution ratio” means the driving force of the rear right wheel (turning outer wheel) when the turning radius R is the minimum radius when turning left. The distribution ratio is maximized, and the driving force distribution ratio of the rear right wheel is decreased toward the equal distribution ratio (50:50) as the turning radius R increases. Then, as shown in FIG. 5 (b), a correction coefficient with a larger value is set as the vehicle speed V increases, and the driving force distribution ratio of the rear right wheel at the left turn determined by the turning radius R is set as a correction coefficient corresponding to the vehicle speed. Correct by That is, the left / right driving force distribution ratio is determined according to the vehicle speed V in consideration of the difference in turning radius and the rotational speed difference between the turning inner wheel and the turning outer wheel (first target left / right wheel driving force distribution ratio setting means).

  In step S11, following the left and right wheel driving force distribution control in step S10, it is determined from the vehicle position information and map information whether or not the vehicle has passed the turning point. If NO, the process returns to step S10. If YES, Move to return.

  In step S12, following the determination that there is a course setting in step S1, it is determined whether the course in which the vehicle is traveling is a GPS registered course registered in the navigation system. If YES, the process proceeds to step S13. If NO, move to return.

  In step S13, following the determination that the vehicle traveling course in step S2 is a GPS registered course, corners (such as crossroads and Y-time roads) registered as turning points based on the vehicle position information, map information, and vehicle speed. It is confirmed whether or not the vehicle has arrived in the vicinity. If NO, the determination in step S13 is repeated, and if YES, the process proceeds to step S14.

  In step S14, following the determination that the vicinity of the corner is reached in step S13, it is determined whether or not there is a winker operation. If NO, the process returns to step S12, and if YES, the process proceeds to step S15. That is, it is confirmed whether or not the driver has a intention to turn by determining whether or not a winker operation is performed.

  In step S15, following the determination that there is a winker operation in step S14, the processing in steps S2 to S7 is executed. When the vehicle reaches the driving force distribution control start point, the process proceeds to step S16.

  In step S16, following the processing of step S2 to step S7, the rear wheel driving force distribution ratio is determined and the front and rear wheel driving force distribution control is started in the same manner as in step S8, and the process proceeds to step S17.

  In step S17, following the start of front and rear wheel driving force distribution control in step S16, it is determined whether or not the vehicle has entered a turning point based on the vehicle position information and the map information, as in step S9. Returning to step S16, the front and rear wheel driving force distribution control is continued. If YES, the process proceeds to step S18.

  In step S18, following the entry determination to the turning point in step S17, the right and left driving force distribution ratio of the rear wheels is determined and the left and right wheel driving force distribution control is started as in step S10, and the process proceeds to step S19. To do.

In step S19, following the left and right wheel driving force distribution control in step S18, it is determined whether or not the vehicle speed has sharply decreased. If NO, the process proceeds to step S21, and if YES, the process proceeds to step S20 ( Deceleration detection means).
Here, the rapid decrease determination of the vehicle speed is performed, for example, by differentiating the vehicle speed information to obtain the vehicle acceleration / deceleration, and the calculated vehicle deceleration being lower than the set deceleration.

In step S20, following the sudden decrease determination of the vehicle speed in step S19, the driving force distribution is reset by the steering angle θ, and the process proceeds to step S21.
Here, as shown in FIG. 6, “resetting the rear wheel driving force distribution ratio” uses the value obtained by dividing the vehicle speed V by the steering angle θ as the horizontal axis, and the rear wheel driving force increases as the value of V / θ increases. It is determined by the characteristic of reducing the distribution ratio Tr. In other words, the rear wheel driving force distribution ratio Tr decreases as the vehicle speed increases at the same steering angle, and the rear wheel driving force distribution ratio Tr decreases as the steering angle decreases at the same vehicle speed V. When the rear wheel driving force distribution ratio is determined, the target front wheel driving force and the target rear wheel driving force are re-established based on the total driving force determined by the required driving force at that time and the rear wheel driving force distribution ratio. The control for changing the driving force so as to obtain the newly set target front wheel driving force and target rear wheel driving force is started (second target front and rear wheel driving force distribution ratio setting means).
In addition, as shown in FIG. 7 (a), “determining the left / right wheel driving force distribution ratio” is the driving force of the rear right wheel (turning outer wheel) when the steering angle θ is close to the neutral position when turning left. The distribution ratio is an equal distribution ratio (50:50), and the driving force distribution ratio of the rear right wheel is increased as the steering angle θ increases. Then, as shown in FIG. 7B, the correction coefficient is set to a larger value as the vehicle speed V increases, and the driving force distribution ratio of the rear right wheel at the left turn determined by the steering angle θ is set as a correction coefficient corresponding to the vehicle speed. Correct by That is, the left / right driving force distribution ratio is determined according to the vehicle speed V in consideration of the difference in turning radius and the rotational speed difference between the turning inner wheel and the turning outer wheel (second target left / right wheel driving force distribution ratio setting means).

  In step S21, following the resetting of the driving force distribution based on the steering angle in step S20, it is determined whether or not the vehicle has passed the turning point based on the vehicle position information and the map information. If NO, the process returns to step S18, YES In case of, move to return.

[Driving force distribution control operation]
If the vehicle is traveling on a traveling course without a course setting, in the flowchart of FIG. 2, the process proceeds to step S1, step S2, step S3, step S4, step S5, step S6, step S7, and step S7. Until it is determined that the vehicle has reached the determined driving force distribution control start point, the vehicle position confirmation from step S2 to step S6, the traveling course information confirmation, the confirmation of the turning radius of the next corner, and the distance confirmation to the corner -The process of determining the driving force distribution control start point is repeated.

  When the vehicle reaches the determined driving force distribution control start point, the process proceeds from step S7 to step S8 to step S9. In step S8, the vehicle speed V is determined until it is determined that the vehicle has entered the turning point. The front and rear wheel driving force distribution control based on the turning radius R is executed prior to the turning point entering.

  When the vehicle enters the turning point, the process proceeds from step S9 to step S10 to step S11. In step S10, the left and right wheels are determined by the vehicle speed V and the turning radius R until it is determined that the vehicle has passed the turning point. Driving force distribution control is added to the front and rear wheel driving force distribution control.

  On the other hand, when the host vehicle is traveling on a traveling course that is grasped in advance by course setting by the navigation system, the process proceeds from step S1 to step S12 in the flowchart of FIG. Step S15 → Step S16 only when all of the following conditions are met: the condition that the course is a GPS registration course, the condition that the vehicle has reached the corner in the next step S13, and the condition that the winker operation is performed in the next step S14. → Proceeding to step S17, the processing of step S2 to step S7 is executed in step S15. When the vehicle reaches the determined driving force distribution control start point, the front and rear wheel driving force distribution control based on the vehicle speed V and the turning radius R is performed in step S16 until it is determined in step S17 that the vehicle has entered the turning point. It is executed prior to the entry of the turning point.

  When the vehicle enters the turning point, the process proceeds from step S17 to step S18 → step S19. In step S19, the flow of step S18 → step S19 → step S21 is repeated unless it is determined that the vehicle speed has rapidly decreased. In step S18, the left and right wheel driving force distribution control based on the vehicle speed V and the turning radius R is added to the front and rear wheel driving force distribution control.

  Then, if the vehicle speed sharply decreases while traveling at the turning point, the process proceeds from step S19 to step S20 to step S21. In step S21, the vehicle speed V is determined until it is determined that the vehicle has passed the turning point. And the steering angle θ, the driving force distribution ratio between the front and rear wheels and the left and right wheels is reset, and the front and rear wheel driving force distribution control and the left and right wheel driving force distribution control based on the resetting are executed.

[Driving force distribution control action]
The driving force distribution control device according to the first embodiment uses the GPS 7 and the map information system 8 to set the torque distribution start point in advance by using the GPS 7 and the map information system 8 to distribute the driving force to the auxiliary driving wheels (rear wheels) when the vehicle turns. It was made for the purpose of reducing the uncomfortable feeling caused by sudden application of driving force and reducing the load on the drive system components.

Therefore, the driving force distribution control operation when the next turning point where the host vehicle approaches is a left turn will be described with reference to FIG.
First, at the current time T1, the vehicle position is confirmed, the traveling course information is confirmed, the turning radius R of the next corner is checked, and the distance L to the corner (to the vehicle and the turning point) is checked. Is called. Then, the control start point (set distance to the corner) is determined by the vehicle speed V and the turning radius R of the host vehicle using the map shown in FIG. The determination of the control start point is such that the higher the vehicle speed V is, the further away the start point of the driving force distribution control is from the turning point, the smaller the turning radius R of the turning point at which the vehicle is scheduled to enter next is the smaller radius. A point.
This is because the time required for the vehicle to reach the turning point becomes shorter as the vehicle speed V is higher, and the turning radius R of the turning point at which the vehicle is scheduled to enter next is smaller. This is because the driving force distribution control amount increases.
In this way, by setting the start timing of the driving force distribution control based on the vehicle speed V and the turning radius R, the front wheel driving force change characteristic and the rear wheel driving force change from the driving force distribution change start time T2 to the steering operation start time T3. Regardless of whether the vehicle speed V is high or small and the turning radius R is large or small, the characteristic can always be a change gradient due to a gentle inclination, and a shock due to a sudden change in driving force distribution can be reduced.

Next, at the driving force distribution change start time T2 when the host vehicle reaches the control start point, the change control of the front and rear wheel driving force distribution ratio is started based on the vehicle speed and the turning radius R, and the solid line driving force characteristic of FIG. As shown, between the driving force distribution change start time T2 and the steering operation start time T3 (= turning point arrival time), the front wheel driving force is gradually reduced without abruptly reducing the driving force distribution. The rear wheel driving force is gradually increased with an increase characteristic corresponding to the force decrease characteristic.
That is, when the front and rear wheel driving force distribution control assumed at the time of turning is a front-wheel drive based hybrid vehicle as in the first embodiment, when the vehicle starts turning with front wheel driving, the higher the vehicle speed V is, the more The smaller the radius R, the higher the understeer tendency, so that the oversteer moment is generated.
In the conventional front and rear wheel driving force distribution control, as shown by the dotted line driving force characteristics in FIG. 8, the steering operation start time T3 is set as the start timing, the front wheel driving force is rapidly decreased, and the rear wheel driving force is rapidly increased. Is done.
In contrast, in the first embodiment, the driving force distribution control start timing assumed at the time of turning is set to a time point before starting the steering operation for turning (driving force distribution change start time T2), and the driving force distribution change is performed. By executing prior to the start time T2, it is possible to reduce the front wheel driving force with a gentle gradient and increase the rear wheel driving force with a gentle gradient.
As a result, the starting current to the rear motor 2b can be reduced, the driving system load can be reduced, and the uncomfortable feeling given to the driver can be reduced.

Next, at the steering operation start time T3 to reach the turning point, left and right wheel driving force distribution control for making the right wheel driving force larger than the left wheel driving force out of the driving force distributed to the rear wheels is started. As shown by the solid line rear wheel driving force characteristics, the right wheel driving force and the left wheel driving force are different from each other between the steering operation start time T3 and the steering operation end time T4.
That is, in the left and right wheel driving force distribution control assumed when turning left, when turning with the left and right wheel driving force distribution being equally distributed, the smaller the turning radius R, the lower the turnability, and In the case of the same turning radius R, the higher the vehicle speed V, the lower the turning performance, so that the driving force of the right wheel, which is the outer turning wheel, is increased so that the counterclockwise yaw moment is generated in the vehicle. This is done by reducing the driving force of the left wheel.
And since the start timing of the conventional left and right wheel driving force distribution control is premised on the front and rear wheel driving force distribution control in which the driving force is distributed to the left and right rear wheels, the front and rear wheel driving force distribution control is close to the end. It is the timing after waiting for the time or end time.
On the other hand, in the first embodiment, the front and rear wheel driving force distribution control is executed in advance from the driving force distribution change start time T2, so the start of the left and right wheel driving force distribution control assumed when turning left is started. The timing is the time point of the steering operation start time T3, and it is possible to obtain the turning ability with good response from the beginning of turning with a high response request.

When the vehicle is traveling on a traveling course that is known in advance, the vehicle traveling course is a GPS registered course, the condition that the vehicle has reached the vicinity of the corner, and the driver turning with a turn signal operation When the intention condition is satisfied and the vehicle reaches the determined driving force distribution control starting point, the front and rear wheel driving force distribution control based on the vehicle speed V and the turning radius R is started before entering the turning point. The
Therefore, in the case of a traveling course that has been grasped in advance, not only a course with a large turning radius that can bend without reducing the vehicle speed, but also a course that travels at a low vehicle speed, such as a crossroad or a Y-shaped road. It becomes possible to cope with this control.

If the vehicle speed V changes greatly to the deceleration side during a crossroad turn or the like, the set driving force distribution is reset, and the driving force distribution of the front and rear wheels and the left and right wheels is determined from the steering angle θ and the vehicle speed V at the time of reacceleration. The ratio is reset, and the driving force distribution control according to the vehicle speed V and the turning radius R is switched to the driving force distribution control according to the vehicle speed V and the steering angle θ.
That is, for example, if the vehicle is restarted in a situation where the vehicle is stopped by waiting for a crossing pedestrian or a situation where the vehicle is greatly decelerated while turning on a crossroad, the balance of driving force may be lost, and driving stability may be reduced. Therefore, in such a situation where re-acceleration is performed, turning can be smoothly resumed by resetting to the optimal driving force distribution according to the steering angle at the time of re-acceleration.

Next, the effect will be described.
In the vehicle driving force distribution control apparatus according to the first embodiment, the effects listed below can be obtained.

  (1) In a vehicle provided with a driving force distribution control means for controlling the driving force distribution of at least one of the front and rear wheels and the left and right wheels, the driving force distribution control means schedules the vehicle to enter next on the traveling course. Since the driving force distribution control that is assumed in advance is executed before the start of turning based on the turning point information to be turned, it is possible to reduce the uncomfortable feeling given to the driver and reduce the load on the drive system components when turning the vehicle.

  (2) Provided is a control start point determining means (step S6) for determining a start point of the driving force distribution control, and the driving force distribution control means drives in advance when the host vehicle reaches the determined start point. Since the force distribution control is started, variations in the start timing of the driving force distribution control can be suppressed.

  (3) The control start point determination means (step S6) performs driving force distribution control as the host vehicle speed V is higher and as the turning radius R of the turning point at which the host vehicle is scheduled to enter next is the smaller radius. Because the starting point of the vehicle is determined to be a point away from the turning point, the fluctuation of the arrival time from the start of the driving force distribution control to the turning point is suppressed regardless of the vehicle speed V, and the turning radius R is small or large. Regardless of the vehicle speed V and the turning radius R, the optimal control start timing can always be obtained regardless of the vehicle speed V and the turning radius R.

  (4) A traveling course determination means (step S1) is provided for determining whether or not the traveling course is grasped in advance by setting the traveling course using the navigation system, and the driving force distribution control means grasps in advance. When driving on a course, the winker operation is performed in a state where the arrival at the vicinity of the turning point is confirmed, and when the vehicle reaches the determined starting point, the driving force distribution control assumed in advance is started. Therefore, this driving force distribution control can be used not only for courses with a large turning radius that can bend without reducing the vehicle speed, but also for courses that run at low vehicle speeds, such as crossroads and Y-shaped roads. it can.

  (5) First target front and rear wheel driving force distribution ratio setting means (step S8) for presetting a first target front and rear wheel driving force distribution ratio based on the vehicle speed V and the turning radius R; A first target left and right wheel driving force distribution ratio setting means (step S10) for presetting one target left and right wheel driving force distribution ratio, and the driving force distribution control means is configured to satisfy a driving force distribution control start condition. The front and rear wheel driving force distribution control for gradually changing the front and rear wheel driving force distribution ratio toward the first target front and rear wheel driving force distribution ratio is started. In order to start the obtained left / right wheel driving force distribution control, it is possible to obtain the optimal front / rear wheel / left / right wheel driving force distribution ratio according to the vehicle speed V and the turning radius R, and to precede the front / rear wheel driving force distribution control. Therefore, the start of the left and right wheel drive force distribution control It is possible to obtain a turning ability with good response from the beginning of turning with a high response request.

  (6) Second target front / rear wheel driving force distribution ratio setting means (step S20) for setting a second target front / rear wheel driving force distribution ratio based on the vehicle speed V and the steering angle θ, and second based on the vehicle speed V and the steering angle θ. A second target left / right wheel driving force distribution ratio setting means (step S20) for setting the target left / right wheel driving force distribution ratio and a deceleration detecting means (step S19) for detecting deceleration of the host vehicle are provided, and the driving force distribution is provided. When the control means detects the deceleration of the host vehicle after entering the turning point, the control means resets the control target to the second target front / rear wheel driving force distribution ratio and the second target left / right wheel driving force distribution ratio. In a situation where re-acceleration such as turning is performed, turning can be smoothly resumed by resetting the left and right wheel driving force distribution ratio according to the steering angle θ.

  (7) The vehicle includes a first drive source that drives one of the front and rear wheels, a second drive source that drives the other auxiliary drive wheel of the front and rear wheels, a GPS 7, and a map information system. 8 is a hybrid four-wheel drive vehicle, and therefore, in the hybrid four-wheel drive vehicle in which the front wheel drive force change and the rear wheel drive force change are performed by the respective drive source responsiveness, the driver is effectively turned when turning the vehicle. It is possible to reduce the uncomfortable feeling given to the vehicle and to reduce the load on the drive system components.

  (8) Since the first drive source is at least one of an engine and a motor and the second drive source is a motor, the front wheel drive force change and the rear wheel drive force change are performed in a highly responsive motor for a short time. In a hybrid four-wheel drive vehicle, which is performed suddenly and causes uncomfortable feelings due to the application of driving force and a problem of increased load on driving system parts, the vehicle turns while reducing the uncomfortable feeling given to the driver and the load on the driving system parts. Sometimes driving force distribution control with a large control amount can be applied.

  The vehicle driving force distribution control device according to the present invention has been described based on the first embodiment. However, the specific configuration is not limited to the first embodiment, and each claim of the claims Design changes and additions are allowed without departing from the gist of the invention.

  In the first embodiment, the GPS and the map information system are installed, and the application example to the vehicle that obtains the vehicle position information and the turning radius information is shown. For example, the vehicle position with respect to the preceding vehicle is recognized by the inter-vehicle sensor, It is also possible to receive turning information from an inter-vehicle communication or an infrastructure installed in a traveling course and to execute a driving force distribution control that is assumed in advance before the start of turning. In short, it is only necessary that the turning point information on which the vehicle plans to enter next on the traveling course can be obtained.

  In the first embodiment, as an example of the driving force distribution control means, the front and rear wheel driving force distribution control is started from the control start point before the start of turning, and the left and right wheel driving force distribution control is started when the turning point is reached. In a vehicle equipped with only the front and rear wheel driving force distribution control means, it is possible to simply execute the front and rear wheel driving force distribution control that is assumed in advance before the start of turning, or the left and right wheel driving force distribution control. In a vehicle equipped with only the means, the left and right wheel driving force distribution control assumed in advance may be executed only before the start of turning. In short, any driving force distribution control means may be used as long as the driving force distribution control assumed in advance is executed from the start of the turn on the basis of the turning point information that the host vehicle is scheduled to enter next on the traveling course.

  In the first embodiment, an example in which the target driving force distribution ratio of the front and rear wheels and the left and right wheels is set by the vehicle speed, the turning radius, and the steering angle is shown, but other information such as road surface μ information, accelerator opening information, etc. In addition, or alternatively, a plurality of pieces of information may be selected from these pieces of information to set the target driving force distribution ratio between the front and rear wheels and the left and right wheels.

  Although the driving force distribution control device for the front wheel drive base vehicle is shown in the first embodiment, the present invention can also be applied to a rear wheel drive base vehicle. Further, the applied vehicle can be applied to, for example, a hybrid vehicle having motors on the left and right rear wheels other than those shown in the first embodiment, and further applicable to an engine driven vehicle as well as the hybrid vehicle. . In the first embodiment, as an example of the driving force distribution control unit, the driving force of the driving source of each of the main driving wheel and the auxiliary driving wheel is directly controlled. However, as described in the related art, in the driving system, The present invention can also be applied to a transfer clutch, a differential limiting clutch, and the like that control the driving force distribution ratio by controlling the clutch engaging force.

1 is an overall system diagram illustrating a hybrid vehicle to which a driving force distribution control device according to a first embodiment is applied. 3 is a flowchart illustrating a flow of a driving force distribution control process executed by the controller according to the first embodiment. It is a figure which shows an example of the control start point map for determining a control start point with the turning radius R and the vehicle speed V which are used in Example 1. FIG. FIG. 3 is a diagram showing an example of a rear wheel driving force distribution ratio map for determining a rear wheel driving force distribution ratio based on a turning radius R and a vehicle speed V used in the first embodiment. The figure which shows an example of the left-right driving force distribution ratio map for determining left-right driving force distribution ratio with the turning radius R used in Example 1, and an example of the correction coefficient table for determining a correction coefficient according to the vehicle speed V are shown. FIG. FIG. 3 is a diagram showing an example of a rear wheel driving force distribution ratio map for determining a rear wheel driving force distribution ratio based on the steering angle θ and the vehicle speed V used in the first embodiment. The figure which shows an example of the left-right driving force distribution ratio map for determining left-right driving force distribution ratio by steering angle (theta) used in Example 1, and an example of the correction coefficient table for determining a correction coefficient according to the vehicle speed V are shown. FIG. It is explanatory drawing which shows the distance to a corner at the time of driving | running | working which is going to turn left, the driving | running | working locus | trajectory of the own vehicle by plane view, a front wheel driving force characteristic, and a rear-wheel driving force characteristic.

Explanation of symbols

1 engine (first drive source)
2a Front motor (first drive source)
2b Rear motor (second drive source)
3a Left front wheel tire (main drive wheel)
3b Right front wheel tire (main drive wheel)
3c Left rear wheel tire (sub drive wheel)
3d Right rear wheel tire (sub drive wheel)
4a Front differential 4b Rear differential 5 Transmission 6 Wheel speed sensor 7 GPS (Global positioning system)
8 Map information system 9 Steering angle sensor 10 Blinker switch 11 Controller 12 High power battery 13a Front inverter 13b Rear inverter

Claims (8)

In a vehicle provided with driving force distribution control means for controlling the driving force distribution of at least one of the front and rear wheels and the left and right wheels,
The driving force distribution control means executes a driving force distribution control that is assumed in advance from the start of a turn on the basis of turning point information that the host vehicle is scheduled to enter next on a traveling course. Power distribution control device. In the vehicle driving force distribution control device according to claim 1,
Provide a control start point determination means for determining the start point of the driving force distribution control,
The driving force distribution control unit starts driving force distribution control assumed in advance when the host vehicle reaches a determined starting point. In the vehicle driving force distribution control device according to claim 2,
The control start point determination means moves the start point of the driving force distribution control away from the turning point as the own vehicle speed is higher and the turning radius of the turning point at which the own vehicle is scheduled to enter next is smaller. A driving force distribution control device for a vehicle, characterized in that it is determined as a point. In the vehicle driving force distribution control device according to claim 2 or 3,
A traveling course determination means for determining whether or not the traveling course is grasped in advance by setting the traveling course using the navigation system is provided.
When the driving force distribution control means is running on a course that has been grasped in advance, the winker operation is performed in a state where arrival near the turning point is confirmed, and the vehicle has reached the determined starting point A driving force distribution control device for a vehicle, which starts a driving force distribution control assumed in advance. In the vehicle driving force distribution control device according to any one of claims 1 to 4,
First target front and rear wheel driving force distribution ratio setting means for presetting a first target front and rear wheel driving force distribution ratio based on the vehicle speed and the turning radius;
First target left and right wheel driving force distribution ratio setting means for presetting a first target left and right wheel driving force distribution ratio based on the vehicle speed and the turning radius;
The driving force distribution control means starts the front and rear wheel driving force distribution control that gradually changes the front and rear wheel driving force distribution ratio toward the first target front and rear wheel driving force distribution ratio when the driving force distribution control start condition is satisfied. When the vehicle enters the turning point, the left and right wheel driving force distribution control for obtaining the first target left and right wheel driving force distribution ratio is started. In the vehicle driving force distribution control device according to claim 5,
Second target front and rear wheel driving force distribution ratio setting means for setting a second target front and rear wheel driving force distribution ratio based on the vehicle speed and the steering angle;
Second target left and right wheel driving force distribution ratio setting means for setting a second target left and right wheel driving force distribution ratio based on the vehicle speed and the steering angle;
A deceleration detection means for detecting deceleration of the host vehicle,
The driving force distribution control means resets the control target to the second target front / rear wheel driving force distribution ratio and the second target left / right wheel driving force distribution ratio when deceleration of the host vehicle is detected after entering the turning point. A driving force distribution control device for a vehicle. In the vehicle driving force distribution control device according to any one of claims 1 to 6,
The vehicle includes a first drive source that drives one of the front and rear wheels, a second drive source that drives the other auxiliary drive wheel of the front and rear wheels, a global positioning system, and a map information system And a driving force distribution control device for a vehicle. In the vehicle driving force distribution control device according to claim 7,
The vehicle driving force distribution control device according to claim 1, wherein the first driving source is at least one of an engine and a motor, and the second driving source is a motor.

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